This invention relates generally to pipe fitting, and more particularly to an offset steam trap.
Steam traps are actually condensate traps, installed in steam lines to remove water which condenses from the steam and would, if not removed, accumulate at low spots, presenting flow impediments and other inefficiencies.
Older systems had inverted bucket-type condensate traps, which contained moving parts and were prone to failure. Those were replaced by fixed-orifice devices, exemplified by U.S. Pat. Nos. 3,715,870 and 3,877,895. Some orifice traps now have replaceable orifices, so that they can be custom fit with an orifice plate or jet of optimum size. Experimentation is often required.
To avoid the need to separate the steam line in order to change the orifice size, some inventors placed a ball valve in the system, and installed a removable jet or orifice in the ball. The valve housing might have a removable lateral plug, so that, with the valve temporarily closed, the jet could be removed and replaced, without having to break down the line. The jet is inserted into a hole through the center of the ball, aligned with the center of a horizontal pipe to which the valve is attached. With such an arrangement, however, some water can accumulate in the pipe, below the level of the orifice. Indeed, a horizontal pipe remains almost half full of water when the orifice is on the center line of the pipe.
In patent application Ser. No. 08/107,982, we described a steam trap of the type just described. The invention described below improves upon the prior device, with the aim of removing all water in the line adjacent the valve.